Answer is c
Work out the moles of 2H2O: 1.80/ (16+1+1) = 0.1
The moles of 2H2 are the same (0.1)
The Mr of H2 is 2
So the mass needed to produce 1.80g of water is
0.1 x 2 = 0.2
Answer:
I think it A not sure if I get it wrong sorry I need points.
Answer:
Theoretical yield of hydrogen is 1.11 g
Explanation:
Balanced equation, 
As Mg remain present in excess therefore HCl is the limiting reagent.
According to balanced equation, 2 moles of HCl produce 1 mol of
.
Molar mass of HCl = 36.46 g/mol
So, 40.0 g of HCl =
of HCl = 1.10 moles of HCl
Hence, theoretically, number of moles of
are produced from 1.10 moles of HCl = 
Molar mass of
= 2.016 g/mol
So, theoretical yield of
= 
The number of H atoms in 3(NH₄)₂CrO₄ = 24
<h3>Further explanation </h3>
The empirical formula is the smallest comparison of atoms of compound forming elements.
A molecular formula is a formula that shows the number of atomic elements that make up a compound.
(empirical formula) n = molecular formula
Subscripts in the chemical formula indicate the number of atoms
The compound of 3(NH₄)₂CrO₄ ( 3 molecules of (NH₄)₂CrO₄ ) :
Number of H :

When it comes into contact with It will turn purple